Presently, ink jet printing includes ejecting or jetting drops of liquid ink from selected nozzles of a print head to form an image on a print media, such as paper. Some ink jet printers receive ink in its liquid form from containers. Other printers receive ink in a solid form.
The ink jet printing (drop-on-demand) industry continues to be an area of growth as printers & printing equipment manufacturers realize the value of personalized digital content. In a common type of inkjet printing, aqueous ink jet print heads eject ink through an array of nozzles using a drop-on-demand strategy when the image content requires that a drop is needed. The image content of any particular image is entirely up to the user to define, and as such it is not required, and extremely unlikely that all of the ink jets in a print head array would be used or exercised in a particular image. Yet a succeeding image print job would likely utilize ink-jets that were not used on the prior image print job.
When an inkjet image forming device prints different jobs on print media (e.g., paper), which may include print jobs that may have different page widths, there invariably are jets that could print on larger width print media but could not be printed on the narrower sheet. Thus, some jets could not be exercised during printing on more narrow print media. When ink jets are not exercised for an extended length of time (e.g., about 30 minutes or more depending on the chemical makeup of the ink) the ink jets tend to dry-up such that the only way to recover the jets is to initiate an ink purge sequence. Even before ink jet dry-up, some ink jets may partially dry-up sufficiently to impair printing accuracy.
An ink purge cycle can cost the operator time (5-10 minutes/purge cycle), and money. Cost of a traditional ink purge cycle may be $3-5 per purge, multiplied 6-8 times per work-shift equals about $20 to $40 per work shift. It would be beneficial to reduce ink purge cycles while maintaining ink jet performance.